Calculate rate constant of first order reaction if concentration of reactant decreases by $90 \%$ in 30…
Calculate rate constant of first order reaction if concentration of reactant decreases by $90 \%$ in 30 minute?
- $2.16 \times 10^{-2} \mathrm{~min}^{-1}$
- $3.52 \times 10^{-2} \mathrm{~min}^{-1}$
- $4.81 \times 10^{-2} \mathrm{~min}^{-1}$
- $\quad 7.67 \times 10^{-2} \cdot \mathrm{~min}^{-1}$
Solution
Concentration decreases by $90 \%$. Hence, $10 \%$ reactant is left after 30 minutes.
$\begin{aligned}
\mathrm{k} & =\frac{2.303}{\mathrm{t}} \log _{10} \frac{[\mathrm{~A}]_0}{[\mathrm{~A}]_{\mathrm{t}}} \\
\mathrm{k} & =\frac{2.303}{30} \log _{10} \frac{100}{10} \\
& =\frac{2.303}{30 \mathrm{~min}}=7.67 \times 10^{-2} \mathrm{~min}^{-1}
\end{aligned}$
Asked in: MHT CET 2024 (10 May Shift 1)
Practice more Chemical Kinetics questions on Aicharya